Polysyncraton pedunculatum Kott, 2001

Kott, Patricia, 2005, New and little-known species of Didemnidae (Ascidiacea, Tunicata) from Australia (Part 3), Journal of Natural History 39 (26), pp. 2409-2479 : 2435

Polysyncraton pedunculatum Kott, 2001

(Figures 5D–F, 19C) Polysyncraton pedunculatum Kott 2001, p 121 and synonymy; 2004a, p 743; 2004b, p 2482 and synonymy.

Distribution

Previously recorded (see Kott 2001, 2004b): South Australia (Great Australian Bight to Kangaroo I.). New record: South Australia (Kangaroo I., SAM E3272).

Description

The laterally flattened, fleshy corms narrowing to a thick, fleshy, basal stalk, have four or five large, sessile common cloacal apertures around the narrow edge of the colony, each with a thin transparent rim. These are especially conspicuous along the centre of the top of each lobe but are depressed into the surface in the preserved colony.

Zooids are in branching double rows or along each side of circular common cloacal cavities. They have short branchial siphons, long tongue-shaped or bifid atrial lips and a long, narrow retractor muscle. Four coils of the vas deferens surround the seven or eight testis follicles.

Remarks

The present species is distinguished from Polysyncraton rica , with which it has been confused, by its stalked aspiculate colony and the position of the sessile common cloacal apertures (which in P. rica are single terminal openings on the top of conical surface elevations). Despite Kott’s (2004b) report of three loose coils of the vas deferens, four are readily detected in a recent revision of zooids from previously recorded as well as the newly recorded colonies described above.